9-1 M INERALS – EARTH ’ S JEWELS

S TANDARD I can use a table of physical properties to classify minerals. ( )

E ARTH ’ S SUBSTANCES DIVIDED INTO 2 CATEGORIES : 1. Organic – contain carbon and hydrogen joined together 2. Inorganic – do not contain carbon and hydrogen joined in that way

W HAT IS A MINERAL ? Mineral – inorganic solid that occurs naturally and has a definite chemical composition and structure

5 C RITERIA TO BE A MINERAL : 1. Must occur naturally 2. Must be inorganic 3. Must exist in nature as a solid 4. Must have uniform chemical composition (every sample made up the same way) 5. Must be made of crystals

I DENTIFYING MINERALS 1. Color 2. Streak – color of mineral in powder form - use a streak plate - may not be same color as overall mineral 3. Luster – way a mineral reflects light - dull, shiny, greasy, pearly, metallic, glassy 4. Density – different minerals have different densities 5. How the mineral breaks - cleavage – breaks regularly along flat surface - fracture – mineral breaks irregularly

I DENTIFYING MINERALS 6. Hardness – some minerals are harder than others - Mohs scale – ranks minerals from softest (talc) to hardest (diamond) on a scale of 1 to 10 - a harder mineral will scratch a softer one but softer will not scratch harder 7. Other properties – react with acids, conductivity, attracted to magnets, glow under certain light

9-2&3 R OCKS AND THE ROCK CYCLE

STANDARDS I can label a diagram that shows the 3 different kinds of rock ( ) I can identify the processes of the rock cycle ( )

W HAT IS A ROCK ? Rock – a naturally occurring solid material that is made up of one or more minerals Rocks are divided into 3 main groups: 1. Igneous 2. Sedimentary 3. Metamorphic - Rocks in each group are formed in a different way

I GNEOUS ROCK Rock that forms when melted rock cools and hardens Some forms from magma (granite) - INTRUSIVE magma – melted rock located below Earth’s surface Others form from lava (basalt) - EXTRUSIVE lava – magma, or melted rock, that reaches Earth’s surface

S EDIMENTARY ROCK Form from deposited pieces of rock called sediments Wind and moving water form pebbles and sand by breaking rock Wind and water carry these pieces away and deposit them in new places Over time layers of sediment build up and the weight compresses them together along with chemical changes to cement the sediments together Examples: limestone and sandstone

M ETAMORPHIC ROCK Formed when heat and pressure cause chemical change in rock Igneous and sedimentary can be changed to this Metamorphic rocks can also change to other metamorphic rocks Examples: gneiss and slate

T HE ROCK CYCLE Any of the 3 major kinds of rock can change into one of the other types Rock cycle – ongoing process of change that rock undergoes Many different pathways the rock can follow